Yeah...my belly is gonna HURT! I just got my newest workout DVD, Cathe Friedrich's Core Max, from her Hardcore series. Included on the disc are 3 20 minute workouts...one using only a mat, 1 using fitness ball, and one using fitness ball and medicine ball.
I am no stranger to Cathe's DVDs. Other workouts of hers that I have acquired include Kick Max, Muscle Max, Supersets & Push Pull, Timesaver (5 abbreviated workouts from her Bodyblast series), and Power Hour + (Maximum Intensity Strength & Body Max).
Every time I have had visible upper-body muscle tone it has been the result of doing her workouts regularly. Most of these workouts are 60-90 minutes in length and require some combo of a step, barbell & plates, hand weights, yoga ball, medicine ball, mat...pretty equipment intensive. I don't mind this--except for the fact that our living room is tiny, so stuff has to be dragged-out, then dragged-back. Our next home will definitely require a dedicated workout space...for using my Cathe DVDs, but also for our bikes on the trainers. Right now the bikes are taking up the living room, so there's no room for using any of my older Cathe workout discs.
Cathe's workouts are INTENSE (but enjoyable...she is funny and very motivating. She is exactly what I think of when I contemplate the perfect personal trainer). I find myself doing a lot of gasping and swearing. But it's a good hurt. I predict my abs are gonna hurt so good tomorrow night! I have done some shorter abs segments on other DVDs of hers and they are tough. I'm really not looking forward to pikes on the ball--I never did figure out how to do that without crashing to the floor.
I am currently working 2 ab workouts into my training schedule each week. This will allow me 1.5 weeks between repeating any workouts, so this will keep the "muscle confusion" effectively challenging my core. I will likely stick to the mat-only routine for the first couple of weeks, since adding the balls will add more difficulty than I'm certain my belly and lower back could handle, at the moment.